Unfocused electrohydraulic lithotripter

ABSTRACT

Electrohydraulic lithotripters comprising a plurality of electrohydraulic probes are disclosed. Each probe of the plurality of probes comprise a first electrode and a second electrode positioned at a distal end of the probe such that when the probe is discharged, an electric arc between the first electrode and the second electrode produces a shockwave that radiates from the distal end of the probe. A first probe and a second probe of the plurality of probes may be configured to discharge simultaneously or sequentially.

RELATED APPLICATIONS

This application is a continuation of U.S. Non-provisional applicationSer. No. 14/852,051, filed on Sep. 11, 2015, pending, which is acontinuation of International Application No. PCT/IB2014/000275, filedon Mar. 10, 2014, expired, which claims the benefit of U.S. ProvisionalApplication No. 61/775,907, filed on Mar. 11, 2013, expired, all ofwhich are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to electrohydraulic lithotripters, and inparticular, an unfocused electrohydraulic lithotripter.

BACKGROUND

Electrohydraulic lithotripsy, both intracorporeal (“IEHL”) andextracorporeal (“ESWL”), has been used in the medical field, primarilyfor breaking concretions in the urinary or biliary track. ConventionalESWL lithotripsy produces a focused or reflected shockwave that radiatesaxially from a distal end of the lithotripsy electrode. This form oftreatment has been adapted for generating a shockwave projected to aspecific spot within an organism, or at the surface of an organism.Those adaptations utilize various wave shaping methods, usually in theform of elliptical reflection, to project the maximum power to a focalpoint inside an organism or on the surface of an organism. The focalpoint receives the largest impact from the shockwave, with degradationin the strength of the shockwave taking the form of an hourglass-typeshape on both sides of the focal point, the largest impact occurring atthe narrowest part of the hourglass shape.

Techniques for shaping shockwaves produced by electrohydrauliclithotripsy are complex and costly. Significant factors in the focusingand shaping of the shockwave include the shape and positioning of alithotripsy electrode, as well as the power supplied to the electrodes.For these reasons, known ESWL electrohydraulic lithotripters utilize asingle electrode to insure that the impact of the shockwave is maximizedat the intended focal point. However, use of a single focused electrodehas a number of performance limitations, including for example, the sizeof generated wave fronts. Known devices are therefore limited bycomplexity of design, cost, and performance capabilities. Accordingly,improved electrohydraulic lithotripters are desirable.

BRIEF SUMMARY

In one aspect an electrohydraulic lithotripter includes a plurality ofelectrohydraulic probes. Each probe of the plurality of probes has afirst electrode and a second electrode positioned at a distal end of theprobe such that when the probe is discharged in a fluid environment, anelectric arc between the first electrode and the second electrodeproduces a shockwave that radiates from the distal end of the probe. Afirst probe and a second probe of the plurality of probes are configuredto discharge simultaneously.

In another aspect, a distal end of the first probe and a distal end ofthe second probe may be positioned in a plane. Alternatively, a distalend of the first probe may be positioned in a first plane and a distalend of the second probe may be positioned in a second plane, where thefirst plane is different than the second plane.

In another aspect, the electrohydraulic lithotripter includes a thirdprobe. A central axis of the first probe, a central axis of the secondprobe, and a central axis of the third probe may not all be positionedin a same plane. The first probe, the second probe, and the third probemay be configured to discharge simultaneously.

In another aspect, an electrohydraulic lithotripter includes a pluralityof electrohydraulic probes. Each probe of the plurality of probes has afirst electrode and a second electrode positioned at a distal end of theprobe such that when the probe is discharged in a fluid environment, anelectric arc between the first electrode and the second electrodeproduces a shockwave that radiates from the distal end of the probe. Afirst probe and a second probe of the plurality of probes are configuredto discharge sequentially.

In another aspect, a distal end of the first probe and a distal end ofthe second probe may be aligned in a plane. Alternatively, a distal endof the first probe may be positioned in a first plane and a distal endof the second probe may be positioned in a second plane, where the firstplane is different than the second plane.

In another aspect, the electrohydraulic lithotripter includes a thirdprobe. A central axis of the first probe, a central axis of the secondprobe, and a central axis of the third probe may not all be positionedin a same plane. The first probe, the second probe, and the third probemay be configured to discharge sequentially.

In yet another aspect, an electrohydraulic lithotripter includes atleast one electrohydraulic probe. Each probe of the at least one probehas a first electrode and a second electrode positioned at a distal endof the probe, such that when the probe is discharged in a fluidenvironment, an electric arc between the first electrode and the secondelectrode produces a shockwave that radiates from the distal end of theprobe. A flexible encapsulating member at least partially surrounds thedistal end of each probe of the at least one probe. A plate positionedrelative to the distal end of each probe of the at least one probereceives the shockwave that radiates from the distal end of each probe.

In another aspect, the plate may be positioned within the flexibleencapsulating member. Alternatively, the plate may be positioned outsidethe flexible encapsulating member, in which case, the plate may becoated with a medicament.

In another aspect, the plate may include at least one opening.

In another aspect, the plate may be formed of a rigid material.Alternatively, the plate may be formed of a flexible material.

In another aspect, the at least one probe includes two or more probes.

In yet another aspect, an electrohydraulic lithotripter forextracorporeal administration of electrohydraulic lithotripsy includesat least one electrohydraulic probe. Each probe of the at least oneprobe has a first electrode and a second electrode positioned at adistal end of the probe, such that when the probe is discharged in afluid environment, an electric arc between the first electrode and thesecond electrode produces an unfocused shockwave that radiates from thedistal end of the probe.

In another aspect, the electrohydraulic lithotripter may becharacterized by the absence of a flexible encapsulating member at leastpartially surrounding the distal end of each probe of the at least oneprobe. Alternatively, the electrohydraulic lithotripter may furtherinclude a flexible encapsulating member extracorporeally positionableagainst a tissue, the flexible encapsulating member at least partiallysurrounding the distal end of each probe of the at least one probe.

In another aspect, the at least one probe comprises a first probe and asecond probe. The first probe and the second probe may be configured todischarge simultaneously, or the first probe and the second probe areconfigured to discharge sequentially.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view of an electrohydraulic lithotripter havinga single electrohydraulic probe;

FIG. 1B is a perspective view of the electrohydraulic lithotripsy probeof FIG. 1A, shown without the flexible encapsulating member;

FIG. 1C is a cross-sectional view of the tip of the electrohydrauliclithotripsy probe of FIG. 1B;

FIG. 2A is a perspective view of a second embodiment of anelectrohydraulic lithotripter having two electrohydraulic probes;

FIG. 2B is a perspective view of the electrohydraulic lithotripsy probesof FIG. 2A, shown without the flexible encapsulating member;

FIG. 3A is a perspective view of a third embodiment of anelectrohydraulic lithotripter having three electrohydraulic probes;

FIG. 3B is a perspective view of the electrohydraulic lithotripsy probesof FIG. 3A, shown without the flexible encapsulating member;

FIG. 4A is a perspective view of a fourth embodiment of anelectrohydraulic lithotripter having four electrohydraulic probes;

FIG. 4B is a perspective view of the electrohydraulic lithotripsy probesof FIG. 4A, shown without the flexible encapsulating member;

FIG. 5A is a perspective view of a fifth embodiment of anelectrohydraulic lithotripter having five electrohydraulic probes;

FIG. 5B is a perspective view of the electrohydraulic lithotripsy probesof FIG. 5A, shown without the flexible encapsulating member;

FIG. 5C is a side view of the electrohydraulic lithotripsy probes ofFIG. 5B;

FIGS. 6A-D are illustrations of the wave shapes and patterns achievableby the disclosed embodiments;

FIGS. 7A-C are exemplary illustrations of a plate useable with any ofthe embodiments described herein;

FIGS. 8A-E are various perspective and side views of an alternativelyshaped lithotripsy probe tip;

FIG. 9 is an illustration of another alternatively shaped lithotripsyprobe tip; and,

FIG. 10 is an illustration of another alternatively shaped lithotripsyprobe tip.

DETAILED DESCRIPTION

The present disclosure is directed to unfocused electrohydrauliclithotripsy (“EHL”) for use both intracorporeally and extracorporeally.Generally, EHL probes include a first electrode and a second electrodepositioned at a distal end of the probe. A difference in voltagepolarities between the first and second electrodes causes an electricarc, resulting in a shockwave that radiates from the lithotripsy probe.Depending on the shape and positioning of the electrodes, the shockwavemay be focused toward a specific region of tissue.

As described herein, unfocused EHL is accomplished by using at leastone, and in some cases two or more, EHL probes. The administration ofunfocused EHL may be advantageous, for example, in the creation ofvarious shockwave strengths, wave front sizes, wave shapes, or to varythe frequency of shockwaves, as desired, for the treatment of tissues.Such treatments could range, for example, from lightly “massaging” atissue, to tissue oblation, or cellular disturbance, and potentialcellular modification. Areas that may benefit from this treatment couldinclude, for example, tumors, decubitus ulcers, wounds, bone spurs,calcium deposits, arthritic areas, etc.

In one implementation, the EHL probes described below may be deliveredto a proper channel of a heart by threading (or pre-loading) the EHLprobes through a center lumen of a catheter or balloon device. Thecatheter may be threaded through appropriate veins or arteries toaddress concretion either forming in vessels or even in the valves ofthe heart or other organs. In other implementations, the EHL probesdescribed below may be delivered to a small lumen of a body organ forthe purpose of disturbing or disrupting (distressing) tissue of the bodyorgan in such a way as to cause a stricture or a “scarring” of thetissue for the purpose of creating a permanent stricture or blockage ofthe lumen. In other implementations, the EHL probes described below maybe used extracorporeally, for example, by positioning a fluid-filledencapsulating member that encapsulates the EHL probe(s) in contact withthe tissue to be treated, or by placing the target tissue (e.g., a bonespur on a foot) and the EHL probe(s) in a fluid-filled basin.

Referring to FIGS. 1A-C, a first embodiment of an electrohydrauliclithotripter 100 is shown. The electrohydraulic lithotripter 100includes an EHL probe 110 having a lithotripsy probe tip 101, aninsulating body 102, a first electrode 104, and a second electrode 106.In one implementation, the first electrode 104, the second electrode106, or both, includes an electrically conductive material such ascopper, silver, or stainless steel.

As shown in this embodiment, the first electrode 104 and the secondelectrode 106 of the EHL probe 110 are cylindrical, with the secondelectrode 106 concentrically aligned with first electrode 104. Aninsulating material 107 is disposed in the annular gap formed betweenthe first electrode 104 and the second electrode 106. The distal end ofthe first electrode 104 is annular, whereas the distal end of the secondelectrode 106 is circular. However, it is envisioned that other EHLprobes having electrodes of different shapes and orientations may alsobe used without departing from the concepts described herein. Forexample, changing the probe dimensions, particularly the annular gapbetween the first electrode 104 and the second electrode 106, can alterthe strength and the size of the shockwave (e.g., the larger the annulargap, the greater the strength and the size of the shockwave).Alternatively, a probe may include an electrode comprised of an array ofconductive elements.

The first electrode 104 is electrically coupled with a firstelectrically conductive structure (not shown) in the EHL probe 110. Asknown in the art, the first electrically conductive structure may becoupled with an electrical source, such as an electrohydraulic generator(Autolith, Supplied by Northgate Technologies Inc.), used to charge thefirst electrode 104 to a first polarity. The second electrode 106 iselectrically coupled with a second electrically conductive structure 116in the EHL probe 110. As known in the art, the second electricallyconductive structure 116 may be coupled with an electrical source andused to charge the second electrode 106 to a second polarity, which isopposite to the first polarity of the first electrode 104.

In one implementation, the first electrode 104 is an anode and thesecond electrode 106 is a cathode, wherein in other implementations, thefirst electrode 104 is a cathode and the second electrode 106 is ananode. In implementations having more than one probe, it is envisionedthat a single anode may be used with multiple cathodes, or conversely, asingle cathode may be used with multiple anodes. When the firstelectrode 104 is charged to a first polarity via the first conductivestructure and the second electrode 106 is charged to a second, oppositepolarity via the second conductive structure 116, a discharge ofelectricity occurs between the first electrode 104 and the secondelectrode 106 (an electric arc) when the potential between the firstelectrode 104 and the second electrode 106 reaches the breakdown voltagefor the media separating the electrodes.

As shown in this embodiment, at least a portion of the EHL probe tip 101including the first electrode 104 and the second electrode 106 issurrounded by a flexible encapsulating member 118, such as a balloon,comprising a water-tight flexible material, such as Mylar. The flexibleencapsulating member 118 encapsulates a liquid, such as saline. However,other liquids can be used. In general, the less ionic content of thefluid, the greater the breakdown voltage, and the stronger theshockwave, whereas the greater the ionic content, the less the breakdownvoltage, and the weaker the shockwave.

When an electrical arc occurs between the first electrode 104 and thesecond electrode 106 as described above, the electrical arc causes asteam bubble in the liquid of the flexible encapsulating member 118. Thesteam bubble rapidly expands and contracts back on itself. As the steambubble contracts, a pressure wave (a shockwave) is created in the liquidof the flexible encapsulating member 118 that radiates away from the EHLprobe tip 101. In other implementations, a flexible encapsulating member118 does not surround the EHL probe tip 101, for example, when the EHLprobe 100 is used intracorporeally within a fluid-filled body cavity, orwhen the EHL probe 100 is used extracorporeally, such as in afluid-filled basin.

Referring to FIGS. 2A-B, a second embodiment of an electrohydrauliclithotripter 200 is shown. The electrohydraulic lithotripter 200includes a first EHL probe 210 and a second EHL probe 220. The first EHLprobe 210 and the second EHL probe 220 may be constructed and operate inthe same manner as describe above with regards to the EHL probe 110,although it is envisioned that other EHL probes having electrodes ofdifferent shapes and orientations may also be used without departingfrom the 7034/226 concepts described herein. The first EHL probe 210 andthe second EHL probe 220 may be connected together by a band 205.

As shown in this embodiment, the distal ends of the first EHL probe 210and the second EHL probe 220 are aligned, i.e., they lie in the sameplane. In other implementations, the distal ends lie in differentplanes. As also shown in this embodiment, a flexible encapsulatingmember 218 surrounds a distal end of the electrohydraulic lithotripter200. In other implementations, a flexible encapsulating member 218 doesnot surround a distal end of the electrohydraulic lithotripter 200.

Referring to FIGS. 3A-B, a third embodiment of an electrohydrauliclithotripter 300 is shown. The electrohydraulic lithotripter 300includes a first EHL probe 310, a second EHL probe 320, and a third EHLprobe 330. The first EHL probe 310, the second EHL probe 320, and thethird EHL probe 330 may be constructed and operate in the same manner asdescribe above with regards to the EHL probe 110, although it isenvisioned that other EHL probes having electrodes of different shapesand orientations may also be used without departing from the conceptsdescribed herein. The first EHL probe 310, the second EHL probe 320, andthe third EHL probe 330 may be connected together by a band 305.

As shown in this embodiment, the distal ends of the first EHL probe 310,the second EHL probe 320, and the third EHL probe 330 are aligned, i.e.,they lie in the same plane. In other implementations, the distal endslie in different planes. Also as shown in this embodiment, the first EHLprobe 310, the second EHL probe 320, and the third EHL probe 330 arearranged such that their axes lie in the same plane. In otherimplementations, their axis are offset, for example, in a triangularconfiguration. Furthermore, as shown in this embodiment, a flexibleencapsulating member 318 surrounds a distal end of the electrohydrauliclithotripter 300. In other implementations, a flexible encapsulatingmember 318 does not surround a distal end of the electrohydrauliclithotripter 300.

Referring to FIGS. 4A-B, a fourth embodiment of an electrohydrauliclithotripter 400 is shown. The electrohydraulic lithotripter 400includes a first EHL probe 410, a second EHL probe 420, a third EHLprobe 430, and a fourth EHL probe 440. The first EHL probe 410, thesecond EHL probe 420, the third EHL probe 430, and the fourth EHL probe440 may be constructed and operate in the same manner as describe abovewith regards to the EHL probe 110, although it is envisioned that otherEHL probes having electrodes of different shapes and orientations mayalso be used without departing from the concepts described herein. Thefirst EHL probe 410, the second EHL probe 420, the third EHL probe 430,and the fourth EHL probe 440 may be connected together by a band 405.

As shown in this embodiment, the distal ends of the first EHL probe 410,the second EHL probe 420, the third EHL probe 430, and the fourth EHLprobe 440 are aligned, i.e., they lie in the same plane. In otherimplementations, the distal ends lie in different planes. Also as shownin this embodiment, the first EHL probe 410 and the fourth EHL probe 440are arranged such that their axes lie in the same plane, while thesecond EHL probe 420 and the third EHL probe 430 are arranged such thattheir axes lie in the same plane. In other implementations, all axes maylie in the same plane, or they may be arranged, for example, in a squareconfiguration. Furthermore, as shown in this embodiment, a flexibleencapsulating member 418 surrounds a distal end of the electrohydrauliclithotripter 400. In other implementations, a flexible encapsulatingmember 418 does not surround a distal end of the electrohydrauliclithotripter 400.

Referring to FIGS. 5A-B, a fifth embodiment of an electrohydrauliclithotripter 500 is shown. The electrohydraulic lithotripter 500includes a first EHL probe 510, a second EHL probe 520, a third EHLprobe 530, a fourth EHL probe 540, and a fifth EHL probe 550. The firstEHL probe 510, the second EHL probe 520, the third EHL probe 530, thefourth EHL probe 540, and the fifth EHL probe 550 may be constructed andoperate in the same manner as describe above with regards to the EHLprobe 110, although it is envisioned that other EHL probes havingelectrodes of different shapes and orientations may also be used withoutdeparting from the concepts described herein. The first EHL probe 510,the second EHL probe 520, the third EHL probe 530, the fourth EHL probe540, and the fifth EHL probe 550 may be connected together by a band505.

As shown in this embodiment, the distal ends of the first EHL probe 510and the third EHL probe 530, are aligned, i.e., they lie in the sameplane, whereas the distal ends of the second EHL probe 520, the fourthEHL probe 540, and the fifth EHL probe 550 are aligned. In otherimplementations, the distal ends of all probes lie in the same plane.Also as shown in this embodiment, the first EHL probe 510 and the thirdEHL probe 530 are arranged such that their axes lie in the same plane,whereas the second EHL probe 520, the fourth EHL probe 540, and thefifth EHL probe 550 are arranged such that their axes lie in the sameplane. In other implementations, all axes may lie in the same plane, orthey may be arranged, for example, in a circular configuration.Furthermore, as shown in this embodiment, a flexible encapsulatingmember 518 surrounds a distal end of the electrohydraulic lithotripter500. In other implementations, a flexible encapsulating member 518 doesnot surround a distal end of the electrohydraulic lithotripter 500.

As also shown in this embodiment, the electrohydraulic lithotripter 500may include a first channel (or lumen) 560 and a second channel (orlumen) 570 that are each in communication with an interior of theflexible encapsulating member 518. Although only shown in thisembodiment, it should be appreciated that a first channel (or lumen) anda second channel (or lumen) in communication with an interior of aflexible encapsulating member may be included in any of the embodimentsdescribed herein. During operation, the first channel 520 may beutilized to infuse a liquid, such as saline, into an interior of theflexible encapsulating member 518 for the purpose of expanding theflexible encapsulating member 518 and providing a medium for creatingelectrohydraulic effect.

Additionally, the second channel 570 may be utilized to remove theliquid from the interior of the flexible encapsulating member 518 andcollapse the flexible encapsulating member 518. In some implementations,the second channel 570 may further be utilized to degass the fluidwithin the flexible encapsulating member 518 after an electrohydraulicdischarge between electrodes.

The circulation of fluid through the interior of the flexibleencapsulating member 518 using the first and second channels 560, 570may be done through manual means such as a syringe, mechanical meanssuch as a pump, or any other means known in the art.

In some implementations, the first and/or second channels 560, 570 mayinclude one or more valves, membranes, or cartridges to assist ininjecting a fluid into the interior region of the flexible encapsulatingmember 518, removing a fluid from the interior region of the flexibleencapsulating member 518, or degassing the fluid within the interiorregion of the flexible encapsulating member 518.

For example, a valve or membrane positioned in or adjacent to the firstchannel 560 may allow a fluid to flow into the interior region of theflexible encapsulating member 518 while preventing the fluid fromentering the first channel 560 from the interior region of the flexibleencapsulating member 518. Similarly, a valve or membrane positioned inor adjacent to the second channel 570 may allow a fluid to flow out ofthe interior region of the flexible encapsulating member 518 whilepreventing fluid from exiting the second channel 570 and flowing intothe interior of the flexible encapsulating member 518. Further, amembrane or cartridge may be positioned in or adjacent to the secondchannel 570 to assist in degassing fluid within the interior region ofthe flexible encapsulating member 518. Examples of valves that may beutilized include one-way valves produced by Qosina Corp or ValuePlastics. Examples of membranes, such as semipermeable membranes, thatmay be utilized include those produced by W.L. Gore & Associates, Inc.

Each of the previously described embodiments may be used to provideunfocused EHL. The activation of individual EHL probes creates unfocusedshockwaves radiating from each probe. By positioning the probes in acluster or a particular pattern, an almost infinite number of shockwavepatterns may be generated. Such patterns can be used, for example, tocreate larger wave fronts than a single probe, stronger shockwaves, anddifferent wave shapes. In addition, the probes may be fired ordischarged simultaneously, or in sequences, or at various frequencies.Furthermore, the arrangement of probes may be such that distal ends ofthe probes are staggered, or arranged in different planes, therebycreating additional wave shapes or patterns.

A generator may be set to fire or discharge a particular EHL probe atvarying power and at varying frequencies. One suitable generator is theAutolith, supplied by Northgate Technologies, Inc. Other suitablegenerators are shown and described in U.S. Provisional PatentApplication No. 61/684,353, the entirety of which is herein incorporatedby reference. The device could use different capacitors and switchingtechniques to change the output of a particular EHL probe, or probes.Redundant circuitry could be also be used if necessary to discharge alarge number of probes simultaneously, or in specific sequences, or inpatterns, depending on the desired treatment.

By way of example, FIGS. 6A-6D illustrate some of the wave shapes andpatterns achievable by the previously described embodiments. As shown inFIG. 6A, the EHL probes of the electrohydraulic lithotripter 200 may befired or discharged simultaneously, thereby producing a wave fronthaving an increased sized. Alternatively, as shown in FIG. 6B, theprobes of the electrohydraulic lithotripter 200 may be fired ordischarged sequentially to create an alternating waveform. Similarly, asshown in FIG. 6C, the EHL probes of the electrohydraulic lithotripter300 may be fired or discharged simultaneously, thereby producing a wavefront having an even larger size. Likewise, as shown in FIG. 6D, the EHLprobes of the electrohydraulic lithotripter 300 may be fired ordischarged sequentially, thereby creating a cascading waveform. It willbe appreciated that additional wave shapes and patterns may be achievedby applying the same firing or discharge concepts to the otherembodiments described herein.

Furthermore, additional wave strengths, shapes, and patterns may begenerated by altering the shapes and orientations of electrodes withinindividual EHL probes of a particular embodiment of an electrohydrauliclithotripter, for example, by changing the probe dimensions, such as theannular gap between the first electrode and the second electrode.

In embodiments having a flexible encapsulating member, the strength ofthe shockwave(s) delivered to a tissue may be selectively adjusted bychanging the volume of fluid in the flexible encapsulating member.Because the strength of a shockwave delivered to a tissue is dependenton the distance from the distal end of the EHL probe(s) to the tissue,the strength of a shockwave may be increased or decreased by increasingor decreasing the volume of the fluid in the flexible encapsulatingmember. These embodiments may also include means for measuring thedistance between the distal ends of individual EHL probe(s) and theflexible encapsulating member.

In other embodiments, the strength of the shockwave(s) delivered to atissue may be selectively adjusted by axially repositioning particularEHL probes within the electrohydraulic lithotripter. For example, theelectrohydraulic lithotripter 400 includes a first EHL probe 410, asecond EHL probe 420, a third EHL probe 430, and a fourth EHL probe 440.The EHL probes are connected together by a band 405. As shown in FIG.4B, the distal ends of the first EHL probe 410, the second EHL probe420, the third EHL probe 430, and the fourth EHL probe 440 are aligned,i.e., they lie in the same plane. However, a user may axially advance,for example, the first EHL probe 410 and the fourth EHL probe 440,relative to the band 405, the second EHL probe 420, and the third EHLprobe 430, such that the distal ends of the first EHL probe 410 and thefourth EHL probe 440 lie in a different plane than the distal ends ofthe second EHL probe 420 and the third EHL probe 430. These embodimentsmay also include means for locking the positions of the EHL probesrelative to one another.

In other embodiments, the shockwave(s) may be discharged toward aconductive surface, such as a pad or a plate, for purposes oftransferring the shockwave to particular tissues areas. For example, aplate may be used to distribute or spread the shockwave over the surfaceof the plate. Alternatively, a plate having a number of openings may beused to focus the discharged shockwave(s) through the openings to treata targeted tissue area. Such a plate may be made of either flexible orrigid materials, depending on the desired shockwave deflection,absorption, or transfer characteristics, and can be positioned eitherinside or outside of the flexible encapsulating member. If positioned onthe outside of the flexible encapsulating member, the plate may becoated or infused with a medication to assist in the tissue treatment.

FIGS. 7A-7C are exemplary illustrations of a plate 700 useable with anyof the embodiments described herein. As shown in FIG. 7A, the plate 700may have a single, centrally positioned opening 701 intended to allowthe shockwave(s) discharged from the EHL probe(s) to pass therethrough.Or, as shown in FIG. 7B, the plate 700 may include a plurality ofopenings 701, aligned with the EHL probes of the associatedelectrohydraulic lithotripter, for example, the five EHL probes of theelectrohydraulic lithotripter 500. As shown, in FIG. 7C, the plate 700may include a plurality of openings in an arrangement, for example,intended to diffuse the shockwave(s) discharged from the EHL probe(s).Alternatively, the plate may not have any openings.

The recent introduction of endoscopes that are designed to reach moreremote locations in the body has presented various difficulties intrying to reach these areas of the body. In order to fragment anddestroy concretions at remote locations within the body, endoscopes andother instruments, such as electrohydraulic lithotripsy probes, may haveto maneuver through extremely tortuous paths to conduct diagnostic andoperating procedures. For example, bends as sharp as 90 degrees, and insome instances, as much as 120 degrees or more, must be traversed toreach the desired location. Because of frictional forces in the lumensof scopes or catheters, or tubes, and the creases or “wrinkles” thatdevelop in the inner walls of these lumens, it is often very difficultto push delicate devices such as guide-wires, forceps, baskets, lasers,or electrohydraulic lithotripsy probes through the lumens to reach thedesired site.

In the case of lasers and electrohydraulic lithotripsy probes, it isextremely difficult or impossible, partially because of the lack ofstiffness in the laser fiber or lithotripsy probe. Furthermore, the tipof these devices is usually shaped as a square, or includes bevelededges, which have been insufficient to prevent lodging, kinking, orresistance caused from too much friction, to progress past or throughthe tortuous angles, thereby rendering it impossible in some cases forthe laser fibers or electrohydraulic lithotripsy probes to reach thetarget area. Some approaches to obviate these problems have includedincreasing the size and stiffness of the fiber or probe, covering theprobe with more lubricious materials (e.g., Teflon), applying ahydrophilic coating to the probe, and sever beveling of the fiber orprobe tip. While these techniques have led to improvement, they have notsolved the problem sufficiently.

Turning to FIGS. 8A-E, various perspective and side views of analternatively shaped lithotripsy probe tip 718 are shown. Like thepreviously described lithotripsy probe tips, the lithotripsy probe tip718 is disposed on the end of an insulating body 702 of anelectrohydraulic lithotripter. The lithotripsy probe tip 718 may beutilized in place of any of the previously described lithotripsy probetips, as well as in other electrohydraulic lithotripters.

The lithotripsy probe tip 718 is adapted to improve the delivery of anelectrohydraulic lithotripter to a remote location in the body. Asshown, the lithotripsy probe tip 718 is spherically shaped.Significantly, the distal surface of the lithotripsy probe tip 718essentially presents a “round surface” to the structural areas it maycontact. All of the previous improvements (e.g., stiffer shafts,slippery sheaths, hydrophilic coatings, etc.) could be included and usedin conjunction with the improved tip shape. As shown, there would be anopening in the tip, close to tangent or tangent to the rounded surface,so that no edges would be presented to the lumen surfaces that wouldcatch on the interior lumen bends or “wrinkles.” It should beappreciated that the shape of the tip does not have to be perfectlyround, but that the surfaces presented to the lumen walls would have tohave the circular radii necessary to approximate a round or circularsurface.

In a preferred embodiment, the diameter of the spherically shapedlithotripsy probe tip 718 is approximately 1.5 mm (0.585 inches) orless, as that is approximately the largest lumen diameter currently inuse in endoscopes used in urology or gastrointestinal applications. Thediameter could be as small as 0.5 mm for some applications. The tipsize, however, could be larger or smaller depending on the availablelumen, endoscope, or body area being accessed. Ultimately, the size ofthe tip would be governed by the lumen size through which it isthreaded.

In alternative embodiments, the shape of the tip could be any otherrounded shape, including, for example, a “donut” shape, as shown in FIG.9. The “donut” shaped tip could, for example, have a radius of about0.018 inches, a diameter of 0.036 inches, an axial length of 0.025inches, and an inner lumen diameter of 0.008 inches. Alternatively, theshape of the tip could be a bead shape having a spherical head with flator cylindrical sides, as shown in FIG. 10. The bead shaped tip could,for example, have a radius of about 0.026 inches in the spherical head,a diameter of 0.05 inches in the cylindrical sides, an axial length of0.052 inches, and an inner lumen diameter of 0.028 inches. Generaltolerances for these dimensions above could range between +/−0.003 to0.005 inches. It should be appreciated that so long as the lead surfacesof the tip present a “round” surface for contacting the lumen, justabout any shape may be used.

The various lithotripsy probe tips described above may be constructed ofmany types of materials, preferably metal, plastic, or glass. Dependingon the material used, the tip may be integral to the function of thedevice (such as glass in a laser fiber, or metal in a lithotripsy probetip), or could be added on to and/or bonded on an existing tip design.

It is intended that the foregoing detailed description e regarded asillustrative rather than limiting, and that it be understood that it isthe following claims, including all equivalents, that are intended todefine the spirit and scope of this invention.

1-20. (canceled)
 21. An invasive electrohydraulic lithotriptercomprising: an electrohydraulic probe comprising a first electrode and asecond electrode positioned at a distal end of the probe such that whenthe probe is discharged in a fluid environment, an electric arc betweenthe first electrode and the second electrode produces a shockwave thatradiates from the distal end of the probe; a rounded lead contactsurface positioned at a distal end of the probe, where the rounded leadcontact surface is adapted to receive a force opposing advancement ofthe electrohydraulic lithotripter through a lumen.
 22. The invasiveelectrohydraulic lithotripter of claim 21, wherein the rounded leadcontact surface is spherically shaped.
 23. The invasive electrohydrauliclithotripter of claim 22, wherein the rounded contact surface has adiameter of approximately 0.585 inches.
 24. The invasiveelectrohydraulic lithotripter of claim 21, wherein the rounded leadcontact surface is donut shaped.
 25. The invasive electrohydrauliclithotripter of claim 24, wherein the rounded lead contact surface has aradius of approximately 0.018 inches, a diameter of approximately 0.036inches, and an axial length of approximately 0.025 inches.
 26. Theinvasive electrohydraulic lithotripter of claim 21, wherein the roundedlead contact surface is a bead shape positioned at a distal end of theprobe.
 27. The invasive electrohydraulic lithotripter of claim 26,wherein the rounded surface has a radius of approximately 0.026 inches.28. The invasive electrohydraulic lithotripter of claim 21, wherein thefirst electrode and the second electrode are cylindrical electrodes. 29.The invasive electrohydraulic lithotripter of claim 21, furthercomprising: a flexible encapsulating member surrounding at least aportion of the distal end of the probe; a first channel in communicationwith an interior of the flexible encapsulating member and configured toprovide a pathway to infuse the flexible encapsulating member with aliquid; and a second channel in communication with the interior of theflexible encapsulating member and configured to degas the liquid withinflexible encapsulating member.
 30. The invasive electrohydrauliclithotripter of claim 29, wherein the flexible encapsulating membercomprises Mylar.
 31. The invasive electrohydraulic lithotripter of claim21, wherein the electrohydraulic probe is covered with a hydrophiliccoating.
 32. The invasive electrohydraulic lithotripter of claim 21,wherein the electrohydraulic probe comprises metal.
 33. The invasiveelectrohydraulic lithotripter of claim 21, further comprising: a secondelectrohydraulic probe comprising a first electrode and a secondelectrode positioned at a distal end of the second probe such that whenthe second probe is discharged in a fluid environment, an electric arcbetween the first electrode and the second electrode produces ashockwave that radiates from the distal end of the second probe.
 34. Amethod comprising: advancing an invasive electrohydraulic lithotripterthough a lumen, the invasive electrohydraulic lithotripter comprising:an electrohydraulic probe comprising a first electrode and a secondelectrode positioned at a distal end of the probe such that when theprobe is discharged in a fluid environment, an electric arc between thefirst electrode and the second electrode produces a shockwave thatradiates from the distal end of the probe; and a rounded lead contactsurface positioned at a distal end of the probe, where the rounded leadcontact surface is adapted to receive a force opposing advancement ofthe electrohydraulic lithotripter through a lumen; in conjunction withadvancing the invasive electrohydraulic lithotripter through the lumen,positioning the electrohydraulic probe adjacent to a target; anddischarging the probe such that a resulting shockwave radiates from thedistal end of the probe and impacts the target.
 35. The method of claim34, wherein the rounded lead contact surface is one of a bead shape thatis posited at the distal end of the probe, a spherical shape, or a donutshape.
 36. The method of claim 34, where the target is tissue.
 37. Themethod of claim 34, wherein the target is a concretion.